A 16-year-old girl referred to as Runa died in December 2025 following an 18-day detention and interrogation by Japanese authorities that caused severe trauma and emaciation, her mother says [1, 2, 3, 4]. Five months after her release, Runa weighed just 20 kilograms due to the ordeal [1, 2, 3, 4].

Runa was arrested in June 2025 in Hyogo Prefecture for allegedly assaulting a patient at a care facility, but charges were dropped after the 18-day detention period [1, 2, 4]. She maintained her innocence throughout, stating she was trying to stop a patient from biting another by gently pressing on the chin [1, 2, 4].

During detention, Runa was denied contact with her family and could only meet lawyers. She was repeatedly pressured to confess and threatened with placement in a reformatory, with warnings she would not see her mother if she refused to admit guilt [1, 2, 4]. This case is cited as an example of Japan’s "hostage justice" system, in which suspects face prolonged detention and intense pressure to confess [1, 2, 3, 4].

After release, Runa was diagnosed with acute stress disorder, eating disorders, and post-traumatic stress disorder [1, 2, 4]. The prolonged detention and interrogation ultimately caused serious damage to her health.

On June 17, 2026, Runa’s mother filed a lawsuit against the state at Kobe District Court seeking 100 million yen (around US$623,000) in compensation [1, 2, 4]. She said, "My daughter was unrecognisable when she died" and added, "I want to know what happened to her, and why she was arrested, detained and had to die" [1].

Masahiro Sasaki, the lawyer representing Runa's mother, recalled the pressure Runa faced during questioning, quoting interrogators saying, "You did it, didn’t you? Just tell the truth" [4].

The Kobe District Public Prosecutor's Office declined to comment, saying it had not yet received the complaint [4].

Runa was allegedly involved in an assault at a care facility on February 14, 2025, before her arrest in June and subsequent 18-day detention. After charges were dropped roughly a month later, she died in December due to complications from trauma and emaciation linked to her detention [1, 2, 3, 4].